Bicycle crank mechanism



- (No Model.) 3 Sheets-Sheet 1.

H. I. SGHANOK.- BICYCLE CRANK MECHANISM.

No. 592,174. Patented Oct. 19,1897.

Q I Q WITNESSES: //V vs 70/? @4 M WM BY ATTORNEYS.

(No Model.) 3 Sheets-Sheet 2.

H. I. SCHANGK;

BICYCLE CRANK MECHANISM. No. 592,174. Patented Oct. 19,1897.

WITNESSES ATTORNEYS.

E udams PETERS co; vniowiwnodwgsummon n c 3 Sheets- Sheet 3.

(No Model.) v H. I. SGHANGK. BICYCLE CRANK MECHANISM.

No. 592,174. Patented Oct. 19,1897.

UNITED. STATES HENRY I. SOHANCK, OF HOLMDEL,NE\V JERSEY. I

PATE T OFFICE.

BICYCLE CRANK MECHANISM.

SPECIFICATION forming part of Letters Patent No. 592,174, dated October 19, 1897. i Application filed r ne v, 1896. Serial No. 595,837. (NomodelJ To all zulwni, it may concern: I

Be itknown that I, HENRY I. SCHANOK, of

l'lolrndel, in the county of Monmouth and the crank-armsto the driving sprocket-wheel during part of its revolution, whereby a'proportionate increase of power is attained for the propulsion of the vehicle.

The object of my invention is to provide simple, novel features of construction in a de.-

vice of the indicated character which are durable, practical, and very effective in operation, are adapted to reduce to a minimum the friction of working parts, and permit of taking up wear between all said parts where loosenessis liable to occur.

The invention consists in the novel con-.

' struction and combination of parts, as is hereinafter described, and defined in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a side view of a bicycle-frame in part having features'of the invention thereon. Fig. 2 is an enlarged longitudinal sectional view taken substantially on the line 2 2 in Fig. 1. Fig. 3 is a detached side view of the bicycle-frame in part and showing a novel detail of the invention. Fig. 4 is a longitudinal sectional view substantially on the line 4 4 in Fig. 3. Fig. 5 is an enlarged transverse and partly sectional view essentially onthe line 5 5 in Figs. 1 and 16. Fig. 6 is a longitudinal sectional plan of the driving sprocket-wheel and of the arm thereon, the view being taken on theline 6 6 of- Fig. 14. Fig. 7 is a reduced side view of .the bicycle-frame portions that join the crank-shaft boX and of the novel crank mechanism thereon, showing different adj ustments of the latter by full and dotted lines.

- tially on the line 8 8 in Fig. 6.

- larged longitudinal sectional'view essentially on the line 99 in Fig. 1; Fig. lOis an enlarged partly-sectional side view of the driving sprocket-gear and its arms in part, taken'substantially onthe line 10 10 in Fig. 6. Fig. 11 is an enlarged transverse sectional viev; substantially on the line 11 11 in Fig. 1. Fig. 12 is an enlarged detached side view-of the crankshaft for the bicycle-holding mechanism and of a portion of an integral crank-arm thereon. Fig. 13 is an enlarged side view of one of the novel crank-arms and a contained ball-bearing, seen in direction of the arrow 13 inFig. 17 Fig. 14 is'a mainly-sectional plan view of the improved crank mechanism in place on a bicycle-frame shown in 'part, the section being taken substantially on the line 14 14 in Fig. 1. Fig. 15 is alongitudinal sectional view of the hub end on one of the crank-arms of the improved construction detached from the other crank mechanism, showing the interior construction of saidhub end and also. of an attached ring forming a portion of the hub, the section being taken essentially on'the line 15 15 in Fig. 16. Fig. 16 is apartly sectional side view. of the hub end and the-jointed connection of two crank-arms that embodyfeatures of the improvement, taken essentially on the" line 16 16 in Fig. 5. Fig. 17 is an enlarged sectional plan view ofv thecrank-shaft box, the crankshaft therein, and other novel details adjacent thereto and in connection withsaid parts; and Fig. 18 is a detached side view-of the ringclamp and a ball-bearing seat therein, said ring being a portion of ahub end on one of the crank-arms, seen in the direction of'the arrow 18 in Fig. 17.

In the drawings representing an embodimentof my invention, A indicates an upright frame member, B a forwardly-inclined portionjof; the frame, and O O are horizontal rearwardly-extendin g frame portions, all projecting from the shaft-box 10 for the support of other parts, the frame being preferably of the well-known diamond typegenerally used in the manufacture of high-grade safetybicycles. The crank-shaft box 10 is in the form of a light cylindric shell, upon which the frame members A B0 are affixed in any suitable and preferred manner, so as to project in proper directions therefrom. As clearly shown in Figs. 4, 14, and 17, the crankshaft box 10 is provided with two ball-bear- ICO ing seat-rings u, that are respectively affixed therein near the opposite ends of the shell, and have their cupped faces disposed toward said ends of the shaft-box.

The crank-shaft 11 is of a correct length to receive and sustain other parts of the improvement, as will be further explained, it being of a diameter which permits its loose insertion through the fixed seat-rings a in the shaft-box 10,the end portions of the shaft projecting therefrom. The body of the crankshaft 11, that is encircled bythe seat-rings a, is threaded for the reception of the ball-bearing sleeves Z), which are internally threaded to adapt them for an adjustable engagement with the threaded body of the shaft, and an end face on each sleeve 0 is cupped, said cupped faces being disposed opposite the cupped faces ofthe seat-rings a which adapts the paired rings a b at each end of the shaftbox 10 to receive and loosely contain between their opposed cupped surfaces the duplicate series of bearing-balls c, that afford antifrictional support for the shaft in the shaftbox, as clearly shown in Figs. Lt and 17.

An important feature of the invention consists of the peculiarly constructed main sprocket-gear 12 and adjuncts for the same, said gear being in the form of a correctlytoothed ring, that is internally threaded to receive two similar guide-rin d (I, which are peripherally threaded for a screwed engagement with the toothed rim 1?, as best shown in Figs. 6, S, and 10.

The guide-rings (Z are truly bored of equal diameter, and at their exterior edges are counterbored a short distance inwardly, to produce on each ring at its free corner an open annular recess, of somewhat greater diameter than the bore proper of each ring.

011 the exterior of the shaft-box 10, preferably at its endthat is, at the right-hand side of the bicycle-framea bracket-arm 13 is secured, it having a curved foot-piece at one end that is saddled upon and affixed to the box or shell 10, as best shown in Figs. 3 and a There is an elongated aperture e formed in the enlarged free end 6 of the bracketarm, and at a suitable point each side of said arm radial hubs e are formed on the foot portion of the arm 13, said hubs being transversely bored, these perforations and the elongated aperture 6 being designed to receive pro jeeting shanks of ball-bearing rollers 14:. The rollers 1% are of like construction, and are plainly shown in Fig. 2, comprising a cylindric shank f, threaded at one end to receive the clamping-nut f, and diametrically enlarged between its ends, affording a shoulder to bear on the side of the bracket-arm 1.3 or on one of the hubs c when the rollers are secured thereto. The intermediate enlargementf is afforded correct length, and intogral therewith a terminal threaded stem is produced at the end of the shank opposite from the end whereon the nut f is screwed, a cupped ball-bearin g ring 1'' being screwed on the stem f and held in desired adjustment thereon by a jam-nut f". A corner of the collar-like enlargement f of the shankf the body of each roller 1% is grooved on its inner cylindrie surface to receive the series of balls f, and externally is flanged at each side edge of the true cylindrical periphery, as shown in Fig. 2 atf The rollers 14: when in secured position on the bracket-arm 13 all project outwardly, thereby adapting them to enter the guide-rings (Z (Z and dispose the sprocket-gear 12 at the end of the box 10 so as to have clearance therefrom, and also avoid cont-act with the adjacent frame member C, as indicated in Fig. l-i. The flanges f on the roller-rings 14 track in the annular recesses formed to accommodate them on the guide-rings d, and it will be seen in Figs. 8, 14., and 17 that said rings are slightly separated at their inner edges, so that each ring may be partially rotated toward or from the other ring. As is apparent, the guide-rings (Z serve as a track for the support and retention in place of the sprocket-toothed rim 12 on the rollers 11, and to facilitate the location of the rings d on said rollers the elongated aperture 6 at the outer end of the arm is provided, as this enables the roller-shank occupying said aperture to be moved toward the other two rollers 14, that project from the hubs c and thus permit the introduction of all the rollers within the guide-rings, after which the roller at the end of the arm 13 may be outwardly moved in the agerture c and secured by the nut f at a proper point for the free movement of the rings- (1 on said rollers.

In order to hold the guide-rings cl at desired points of lateral adjustment, there is a series of spaced perforations (1 formed in the pcriphery of each ring, which are spirally disposed, so that a pin d for each guide-ring may be inserted first through a perforation in the sprocket-gear rim 12, and thence into an appropriate perforation (ll, said pins bein g held from retraction by the large heads on set-screws (1, whereby the guide-rings may be prevented from turning until wear on their sides is to be compensated for.

On the left-hand end of the crank-shaft 11 there is a crank-arm 15 of ordinary form sccured, there being the usual spindle 15 projected outwardly from the free end of the arm mentioned to receive any approved style of pedal. Between the crank-arm l5 and the end of the shaft-box 10 a jam-nut 1-3" is screwed upon the threaded body of the crankshaft 1], and a flat metallic washer g is located intermediately of the jam-nut and the end of the box 10, these parts 15" g serving to hold the cupped ring I) from turning. The opposite end of the crankshaft 11 projects beyond the sprocket-gear 12 from the box 10 far enough to adapt it for an ellicient con- ICC ' outermost.

nection with important features of the invention, and, as shown in Figs. 12, let, and 17, a crank lever or arm 11 is integrally formed or rigidly secured on the body of the shaft 11, so as to project therefrom in the same direction and substantially parallel with the crank-arm 15, or at a right angle to the axis of the shaft. A suflicient space is provided between the arm 11 and the sprocket-gear rim 12 to accommodate the hubclamping ring 16, that will be hereinafter described.

Exterior of the rigidly-attached or integral arm 11 the shaft end is threaded in two diameters, as shown at h h in Figs. 12, 14, and 17, the portion h of smallest diameter being The hub portion of the fixed arm 11 is rounded at the extremity that slightly projects beyond the body of the shaft 11 opposite from the arm, said hub it being rendered uniform in thickness by areduction of each side of the same, as shown in Figs. 14: and 17. -A rockable crank-arm 17 is furnished as a complementary adjunct, and coacts with the fixed crank-arm 11 and, as shown, the arm 17 consists of an elongated bar, substantially equal in length to that of the fixed arm 11.

The hub end 17 of the crank-arm 17 is peripherally shaped, as shown in Figs. 13 and.

16, being essentially circular with the excep-. tion of two ears 2', that project therefrom at equal distances from the longitudinal center of the hub, which ears are laterally perforated for the reception of the clamping-bolts 'i, a similar perforation being formed in the body of the arm where the hub joins therewith. The hub 17 is centrally and circularly apertured of a correct diameter to receive ball-bearing parts that will be presently described, and said aperture is counterbored on the side that in service is adjacent .to the cient diameter to freely receive said hub end. The hub-ring 16 is afforded a diameter equal to that of the hub on the rockable arm 17, and is provided withthree perforated ears 4?,- which when said parts are assembled lie opposite the ears 2' and perforation of the arm 17, so that the bolts i) may be inserted into the alined perforations of the two sets of ears mentioned. The ends of the headed bolts 71 are threaded, and said screw-cut ends may be screwed into the threads formed in the perforations of the .ears 2' and arm 17, or nuts i may be provided therefor to adapt the bolts mentioned for clamping the ring 16 upon the hub 17. The bore in the ring 16 is of such relative diameter as will permit the introduction of ball-bearing parts therein; and it is to be understood that the body of the shaft 11 is to be passed through the ring 16 from the end that thecrank-arm 15 is secured upon, before the latter is affixed in'place thereon. The shaft 11 is threaded to receive the interiorly-threaded and cupped seat-ring it, that when in place is located near the inner side of the hub of the arm 11, and

on the same side of said hub a complementary cupped seat-ring m is introduced within the bore of the clamping-ring 16, the rings is and m being provided for holding in working position the series of balls at, that complete the ball-bearing for the clamping-ring 16. A felt or other pliable joint-ring 0 is preferably located in an annular recess produced in the face of the ring m, that contacts with the side of the integral hub or arm 11 and in a transverse tapped hole formed in said hub opposite a notch in the edge of the threaded seat-ring k a set-screw o is screwed, so that its inner end will impinge the notched edge mentioned and press on the seat-ring to prevent its rotation and consequent longitudinal movement.

On the opposite end of the cupped seatring m a pliable j oint-rin g p is caused to bear, said joint-ring being bedded in an annular recess formed in the face of the clampingring 16 that is nearest the sprocket-rim 14,

and said dust-excluding joint-ring p is heldin place by the thin ring-clamp p, which is provided with spaced ears at its edge that contact with the periphery of the clampingring 16 and are thereto secured by screws, as shown in Fig. 17.

The construction of the parts composing the ball-bearin g provided for the hub 17 of the rockable crank-arm 17 consists, essentially, of a cupped sleeve-ring h that is adapted to screw on the threaded end portion 77. of the crank-shaft 11, another cupped ring if that encircles the ring 71 being seated in a counterbore of the circular aperture in the hub 17 sufficient space intervening the cupped surfaces of said rings 77, h to permit the introduction of a series of bearing-balls it.

On the extremity h of the shaft 11 a keeper-v nut h is screwed upon the end of the threaded portion h, the nut having close contact with the outerend of the cupped sleeve-ring M, which prevents the latter from unscrewing.

The hub end 17 and clamping-ring 16, that together loosely embrace the hub of the arm 11, are similarly apertured in theinwalls'to allow the body of said crank-arm to project therefrom, a sufficient clearance being afforded at each edge of the fixed arm 11 to allow the arm 17 to rock thereon a suitable degree, as shown at y in Fig. 5, and a jointwasher Z is introduced between the hub ends it and 17.

To exclude dust fromthe ball-bearing at the outer side of the fixed arm and rockable arm, a cap-plate q is provided, which is located at one side in the undercut edge on the rounded periphery of. a shallow recess produced in the exterior face of the hub 17, this engagement of parts holding a portion of the cap-plate on the hub, so that a single screw q, inserted in a tapped perforation of the hub at an opposite point thereon, serves to hold the cap-plate secured in place.

The sprocket-rim 12 has two radial arms 12 oppositely projected therefrom, which are preferably bent as shown in Figs. 6 and 11, which disposes the outer ends of said arms near to the similar sides of the crank-arms 11 and 17.

Suitable enlargements of width are produced on the end portions of the fixed arm 11 and rockable arm 17 which portions are similarly slotted to provide elongated openings r therein, and from each radial arm 12 like ball-bearing rollers 18 are projected, that slidably and pivotally engage these openings or raceways r, as shown in Figs. 1, 7, and 14:. Preferably the rollers 18 are constructed as seetionally shown in Fig. 9, each consisting, essentially, of a shank 3, having one end threaded for the reception of the nut s, that seats in a countersunk depression at the end of one of the radial arms 12" and which surrounds the perforation of the arm mentioned in which the shank s is inserted.

The shank is diametrically enlarged between its ends, as at and thus affords a shoulder which bears on the side of the arm 12 that is adjacent to the crank-arm engagedby the roller 18. An opposite peripheral corner of the enlargement or collar 3 is cupped or rendered concave to afford a bearing for the series of bearing-balls s and from said concave seat the remaining portion 3' of the shank is reduced and threaded, for the reception of a cupped and internally-threaded bearing-ring s The roller-body is in ring form, having a radial flan ge t at the end which encircles the threaded stem .9 the diameter of the roller being proportioned to the width of the raceway 0' it is to occupy and loosely slide in. The inner surface of the annular r0ller-bod y is furnished with a rib near its center of length, which rib is concaved at each side to form bearing-seats that respectively engage with the series of balls .5 and a similar series of balls 8. The bearing-ring s is held in proper adjustment on the stem 8 by anuts that is screwed on the latter outside of the ring, as shown in Fig. 9, and a dust-excluding cap .5 is seen red on the outer end of the roller-body 18, so as to cover the ball-bearing mechanism therein. Preferably a pliable joint is located between the roller-body 18 at its opposite end and the adjacent end of the radial arm 12, whereon the roller is held to revolve, so that dust may not'enter the roller at that point.

The bracket-arm 13 is preferably inclined rearward and downward from a horizontal plane that intersects the axis of the crankshaft 11, as best shown in Fig. 3, which will correspondingly dispose the center of motion 00 for the sprocket-wheel 12 behind the axis 5 of the crank-shaft 11, when parts of the crank mechanism are in relative positions, (indicated in Figs. 1 or 7,) the arm 13 being shown further depressed at its free end in the latter-mentioned figure than is shown in Fig. 1, the degree of inclination of said arm being optional with the constructor of the vehicle.

On the outer side of one slotted end of the rockable crank-arm 17 a bridge or yoke piece it is formed or secured at a point which will permit the outward projection therefrom of a pedal-supporting spindle w; and the axis of said spindle should equalin distance from the axial center of the crank-shaft 11 the length of the fixed crank-arm 15 as defined by the distance between the crank-shaft axis and the center of the pedal-spindle 15. Preferably the side face of the sprocket-gear rim 12 is covered with a thin plate 21, that is supported on the stems f of rollers 14 by any suitable means, said plate being apertured at a correct point for the loose insertion of the shaft 11 through the same, as represented in Figs. 14 and 17.

The operation of the improved crank mechanism is as follows: Assuming that the bracket-arm 13 is inclined on the shaft-box 10, as indicated in Figs. 1 and 7, it will be evident that the eccentricity of the roller-support afforded the driving sprocket-gear 12 with regard to the crank-shaft will dispose the center of rot-a-tive movement had by the sprocketgear mentioned in the same inclined plane with that occupied by the longitudinal axes of the fixed crank-arm 11 and rockable crankarm 17 when said arms assume the position shown by full lines in Fig. 7. It will be seen that the disposal of parts as just described will add the distance between the center of motion a: and the center of the crank-shaft to the length of the rockable arm 17 when the arms 11 and 17 are alined, and thus correspondingly increase the elfective leverage of the rockable arm with regard to the center of motion for the sprocket-gear 12. \Vhen the arms ll" and 17 assume the relative position indicated by dotted lines in Fig. 7, they will incline slightly rearward, as is necessary in order to permit their slidable connection to be maintained with the rollers 18 on the ends of the radial arms 12, and as the centers of the pedal-spindles are now substantially in a vertical plane with the center of motion a for the sprocket-gear 12 it will be evident that the leverage had by the crank-arm 17 will be normal, or, in other words, will be restricted to its length between the crank-shaft center and the center of the pedal-spindle a.

It is obvious that the change of location, due to rotation, that carries the fixed arm 11 into the position occupied by the rockable arm 17, as illustrated in Fig. 7, will adapt the arm 11 to transmit the maximum leverage it has obtained, by addition of the distance between the centers a: and z, to the left-hand cranlearm 15, that is now moving in an are forward of the crank-shaft center.

The. practical increase in effectiveness afforded the crank-arms 15 and 17, due to the peculiar arrangement of parts, is greatly enhanced by the use of the ball-bearing rollers 14 and 18, that serve to reduce the friction of contacting surfaces to a minimum and e11- able Wear to be taken up at all points subjected thereto.

It is apparent that the skeleton support provided for the main sprocket-gear 12 greatly reduces the weight over a solid eccentric previously used for the indicated purpose, and the gear named, if connectedby the usual chain to a gear on the axle of the rear traction-wheel of a bicycle, will effectively transmit rotary motion to said traction-wheel for propulsion of the bicycle.

It will also be seen that the entire crank mechanism herein described is light, strong, shapely, and, capable of production by machinery now in use, so that the improvements may be produced at a moderate cost.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. A crank mechanism having an axle, an arm formed integral with the axle and having a hub running around the axle, a second arm with an orificed end receiving a portion of the axle projecting beyond the hub, a ring receiving a portion of the axle on the opposite side of the hub and secured to the secondnamed arm, a bearing-cone fixed to the axle at a point within the ring, a second bearingcone fixed to the ring, balls inclosed between the two cones, a joint-ring lying against the bearing-cone which is fixed to the first-named ring, a clamp secured to the outer portion of said first-named ring and extending inwardly to hold the joint-ring in place, a screw extending through the hub to engage the cone on the axle and hold the same, a second j ointring at the inner side of the bearing-cone for the first-named ring and engaging the hub, a bearing-cone secured to the axle at a point within the second-named arm, a second bearing-cone secured to the orifice in said secondnamed arm, antifriction-balls interposed between the two last-named bearing-cones, a joint-ring lying against the outer side of the hub of the first-named arm, a nut screwed on the outer extremity of the axle and holding in place the bearing-cone which is carried by said outer extremity, and a cover-plate secured to the second-named arm and inclosing the end of the axle, the second-named arm and the ring which is attached thereto having orifices through which the first-named arm passes, said orifices being larger than the thickness of the first-named arm whereby to permit the second-named arm to have movement independently of the first-named arm, substantially as described.

2. The combination of an axle, a sprocketwheel mounted eccentrically to the axle and having oppositely-projecting parts, an arm fixed to the axle at a point adjacent to the sprocket-wheel and having a hub running around the axle, a second arm held loosely on the axle and alongside of the hub, the projecting parts of the sprocket respectively having sliding and pivotal connection with the arms, and a ring loose on the axle and atthe side of the hub opposite the side having the second arm, the ring and said second arm inclosing the hub of the first arm and being rigidly connected with each other and also having an opening larger than the thickness of the first arm through which opening the said first arm passes and by which the second arm may have slight independent movement on the axle, substantially as described.

HENRY I. SOI-IANCK. Witnesses:

J 0s. 0. HEYER, II. 0. LONGSTREET. 

